look at the crab guys on deadliest catch
some make tons of money in small time period although not always, and how much labor and sleep/family time is lost

many jobs can say that. If I am going to lose $2-$3k on a break for not sorting 300-400 sets, then not sure I would break, that is where most of the profits come and why there is profit outside of a rare lucky pull which in big qty does not matter as much... I mean sure a $300-$500+ card is nice, but when compared to $25k+ is a smaller amount then say $2-$3k of base card sorting
just my opinion
PLUS not sure I could move all the cases that way, unsorted that is, most, but not all, and definitely not on ebay, these guys are direct buyers